Communication entity and a method for transmitting a video data stream

Abstract

A communication entity for transmitting a video data stream at a target transmission bit rate and corresponding method are provided. The communication entity comprises: a first scheduling instance configured to determine a preliminary transmission bit rate for forwarding the video data stream towards the user equipment; and a second scheduling instance configured to determine the target transmission bit rate based on the preliminary transmission bit rate and a set of video bit rates, the set of video bit rates comprising a first video bit rate associated with a first video quality and a second video bit rate associated with a second video quality, the first video bit rate being smaller than the second video bit rate, wherein the second scheduling instance is configured to select the preliminary transmission bit rate as the target transmission bit rate if the preliminary transmission bit rate does not exceed the first video bit rate.

What is claimed is: 
     
       1. A communication entity for transmitting a video data stream towards a user equipment over a communication network at a target transmission bit rate, the communication entity comprising:
 a memory storing instructions; and 
 a processor coupled to the memory to execute the instructions to: 
 determine a preliminary transmission bit rate for forwarding the video data stream towards the user equipment; 
 determine the target transmission bit rate based on the preliminary transmission bit rate and a set of video bit rates, wherein the set of video bit rates comprises a first video bit rate and a second video bit rate, the first video bit rate is associated with a first video quality, the second video bit rate is associated with a second video quality, the first video bit rate is smaller than the second video bit rate, and 
 select the preliminary transmission bit rate as the target transmission bit rate in response to the preliminary transmission bit rate not exceeding the first video bit rate; 
 determine a further preliminary transmission bit rate for forwarding a further video data stream towards a further user equipment; and
 determine a further target transmission bit rate based on the further preliminary transmission bit rate and the set of video bit rates; select the further preliminary transmission bit rate as the further target transmission bit rate in response to the further preliminary transmission bit rate not exceeding the first video bit rate; or 
 determine the further target transmission bit rate based on the further preliminary transmission bit rate and a further set of video bit rates, wherein the further set of video bit rates comprises a third video bit rate and a fourth video bit rate, the third video bit rate is associated with a third video quality, the fourth video bit rate is associated with a fourth video quality, the third video bit rate is smaller than the fourth video bit rate; and select the further preliminary transmission bit rate as the further target transmission bit rate in response to the further preliminary transmission bit rate not exceeding the third video bit rate. 
 
 
     
     
       2. The communication entity according to  claim 1 , wherein the processor further executes the instructions to:
 compare the preliminary transmission bit rate to the second video bit rate in response to the preliminary transmission bit rate exceeding the first video bit rate, and 
 select the second video bit rate as the target transmission bit rate in response to the second video bit rate not exceed the preliminary transmission bit rate; or select the first video bit rate as the target transmission bit rate in response to the second video bit rate exceeding the preliminary transmission bit rate. 
 
     
     
       3. The communication entity according to  claim 1 , wherein the set of video bit rates comprises a plurality of video bit rates associated with a plurality of video qualities, and wherein the processor further executes the instructions to:
 determine a maximum video bit rate among those video bit rates from the plurality of video bit rates that are smaller than the preliminary transmission bit rate, or determine a lowest video bit rate from the plurality of video bit rates that is smaller than the preliminary transmission bit rate, and 
 select the respectively determined video bit rate as the target transmission bit rate. 
 
     
     
       4. The communication entity according to  claim 1 , wherein the processor further executes the instructions to:
 schedule first radio resources of the communication entity for transmission of the video data stream towards the user equipment, and schedule second radio resources of the communication entity for other data communications. 
 
     
     
       5. The communication entity according to  claim 1 , wherein the processor further executes the instructions to:
 receive the preliminary transmission bit rate from the first scheduling instance and schedule radio resources of the communication entity for communication of the video data stream towards the user equipment at the target transmission bit rate; and 
 provide information indicating the scheduled radio resources for communication of the video data stream towards the user equipment at the target transmission bit rate. 
 
     
     
       6. The communication entity according to  claim 1 , further comprising:
 a reception interface configured to cooperate with the processor to receive, over Internet, the video data stream according to the HTTP adaptive streaming technology. 
 
     
     
       7. The communication entity according to  claim 1 , wherein the communication entity comprises:
 a data base configured to store the set of video bit rates, or 
 wherein the processor executes the instructions to: retrieve the set of video data rates from a remote data base over the communication network or over another communication link. 
 
     
     
       8. The communication entity according to  claim 1 , wherein the processor executes the instructions to:
 determine an average transmission bit rate averaging a plurality of transmission bit rates for different video data streams within a time slot, and determine the preliminary transmission bit rate as the average transmission bit rate. 
 
     
     
       9. The communication entity according to  claim 1 , further comprising:
 a transmission interface configured to cooperate with the processor to transmit the video data stream towards the user equipment at the target transmission bit rate. 
 
     
     
       10. The communication entity according to  claim 9 , wherein the transmission interface is configured to transmit the video data stream towards the user equipment over a radio communication network. 
     
     
       11. The communication entity according to  claim 1 , wherein the communication entity is a base station or an evolved Node B (eNodeB). 
     
     
       12. The communication entity according to  claim 1 , wherein the processor executes the instructions to:
 determine a best user equipment i c *(t) from a plurality of user equipments for allocation of radio resource c of the communication entity at a time slot t by the following: 
 
       
         
           
             
               
                 
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         wherein K indicates available radio resources,  r   i (t) indicates a target transmission bit rate for transmission of a video data stream from the communication entity to one of the plurality of user equipments i, γ i (t) indicates a real transmission bit rate for transmission of a video data stream from the communication entity to the respective user equipment i, Γ i   c (t) indicates an instantaneous bit rate for the respective user equipment i at the time slot t for the radio resource c and i v  indicates a user equipment for other data communications with the communication entity. 
       
     
     
       13. A transmission method for transmitting a video data stream towards a user equipment over a communication network at a target transmission bit rate by a communication entity, the transmission method comprising:
 determining a preliminary transmission bit rate for forwarding the video data stream towards the user equipment by a first scheduling instance of the communication entity; 
 determining the target transmission bit rate based on the preliminary transmission bit rate and a set of video bit rates at a second scheduling instance, wherein the set of video bit rates comprises a first video bit rate and a second video bit rate, the first video bit rate is associated with a first video quality, the second video bit rate is associated with a second video quality, the first video bit rate is smaller than the second video bit rate, wherein the second scheduling instance selects the preliminary transmission bit rate as the target transmission bit rate in response to the preliminary transmission bit rate not exceeding the first video bit rate; 
 determining a further preliminary transmission bit rate for forwarding a further video data stream towards a further user equipment; and
 determining a further target transmission bit rate based on the further preliminary transmission bit rate and the set of video bit rates; select the further preliminary transmission bit rate as the further target transmission bit rate in response to the further preliminary transmission bit rate not exceeding the first video bit rate; or 
 determining the further target transmission bit rate based on the further preliminary transmission bit rate and a further set of video bit rates, wherein the further set of video bit rates comprises a third video bit rate and a fourth video bit rate, the third video bit rate is associated with a third video quality, the fourth video bit rate is associated with a fourth video quality, the third video bit rate is smaller than the fourth video bit rate; and selecting the further preliminary transmission bit rate as the further target transmission bit rate in response to the further preliminary transmission bit rate not exceeding the third video bit rate. 
 
 
     
     
       14. The method according to  claim 13 , further comprising:
 comparing, by the second scheduling instance, the preliminary transmission bit rate to the second video bit rate in response to the preliminary transmission bit rate exceeding the first video bit rate, and 
 selecting, by the second scheduling instance, the second video bit rate as the target transmission bit rate in response to the second video bit rate not exceeding the preliminary transmission bit rate or to select the first video bit rate as the target transmission bit rate in response to the second video bit rate exceeding the preliminary transmission bit rate. 
 
     
     
       15. The method according to  claim 13 , wherein the set of video bit rates comprises a plurality of video bit rates being associated with a plurality of video qualities, and the method further comprises:
 determining, by the second scheduling instance, a maximum video bit rate among those video bit rates from the plurality of video bit rates that are smaller than the preliminary transmission bit rate, or determining, by the second scheduling instance, a lowest video bit rate from the plurality of video bit rates that is smaller than the preliminary transmission bit rate; and 
 selecting, by the communication entity, the respectively determined video bit rate as the target transmission bit rate. 
 
     
     
       16. The method according to  claim 13 , further comprising:
 scheduling, by the first scheduling instance, first radio resources of the communication entity for transmission of the video data stream towards the user equipment, and 
 scheduling, by the first scheduling instance, second radio resources of the communication entity for other data communications. 
 
     
     
       17. The method according to  claim 13 , further comprising:
 receiving, by the second scheduling instance, the preliminary transmission bit rate from the first scheduling instance and providing, by the second scheduling instance, the target transmission rate to the first scheduling instance, and 
 scheduling, by the first scheduling instance, radio resources of the communication entity for communication of the video data stream towards the user equipment at the target transmission bit rate, or scheduling, by the second scheduling instance, radio resources of the communication entity for communication of the video data stream towards the user equipment at the target transmission bit rate and to provide information indicating the scheduled radio resources to the first scheduling instance for communication of the video data stream towards the user equipment at the target transmission bit rate. 
 
     
     
       18. The method according to  claim 13 , comprising:
 determining an average transmission bit rate averaging a plurality of transmission bit rates for different video data streams within a time slot, and 
 determining the preliminary transmission bit rate as the average transmission bit rate. 
 
     
     
       19. A non-transitory computer-readable medium storing processor executable instructions for implementing a transmission method for transmitting a video data stream towards a user equipment over a communication network at a target transmission bit rate, the instructions, when executed cause a communication entity to:
 determine a preliminary transmission bit rate for forwarding the video data stream towards the user equipment; 
 determine the target transmission bit rate upon the basis of the preliminary transmission bit rate and a set of video bit rates, wherein the set of video bit rates comprises a first video bit rate and a second video bit rate, the first video bit rate is associated with a first video quality, the second video bit rate is associated with a second video quality, the first video bit rate is smaller than the second video bit rate, and 
 select the preliminary transmission bit rate as the target transmission bit rate in response to the preliminary transmission bit rate not exceeding the first video bit rate; 
 determine a further preliminary transmission bit rate for forwarding a further video data stream towards a further user equipment; and 
 determine a further target transmission bit rate based on the further preliminary transmission bit rate and the set of video bit rates; select the further preliminary transmission bit rate as the further target transmission bit rate in response to the further preliminary transmission bit rate not exceeding the first video bit rate; or 
 determine the further target transmission bit rate based on the further preliminary transmission bit rate and a further set of video bit rates, wherein the further set of video bit rates comprises a third video bit rate and a fourth video bit rate, the third video bit rate is associated with a third video quality, the fourth video bit rate is associated with a fourth video quality, the third video bit rate is smaller than the fourth video bit rate; and select the further preliminary transmission bit rate as the further target transmission bit rate in response to the further preliminary transmission bit rate not exceeding the third video bit rate. 
 
     
     
       20. The non-transitory computer-readable medium of  claim 1 , wherein the instructions, when executed, further cause the communication entity to:
 determine an average transmission bit rate averaging a plurality of transmission bit rates for different video data streams within a time slot, and determine the preliminary transmission bit rate as the average transmission bit rate.